The product pages seem to indicate that the EP500 now has a convex dust cap.

I really like the look of the single aluminum cone drivers on the EP600/800, the Rythmik subs and some other manufacturers. I like the idea of my dust caps not being dented.

So, since you guys probably read AVS or can Google better than I can or are actual audio professionals...

Is it cheaper (or better) to manufacture drivers with a convex dust cap rather than drivers with a single cone or a concave dust cap? Does it improve the radiation pattern? Does the effect vary by frequency?